Cellulose-ether composition



Patented Nov. 12, 1929 UNITED STATES PATENT OFFICE- STE'WART J. CARROLL,OF ROCHESTER, NEW YORK, ASSIGNOR TO EASTMAN KODAK I COMPANY, OFROCHESTER, NEW YORK, A CORPORATION OF NEW YORK .CELLULOSE-ETHERCOMPOSITION Ho Drawing.

This invention relates to a composition of matter in which celluloseether is combined or mixed with other substances, so that the resultingproduct can be advantageously used in the plastic and analogous arts,such for instance as sheet or film manufacture and varnish manufacture.

One object of the .invention is to provide a composition which may bemade into permanently transparent, strong and flexible sheets of filmsof desired thinness, which are substantially waterproof, are unafi'ectedby ordinary photographic fluids, and possess the desired properties of asupport for lightsensitive photographic coatings, Another object of myinvention is to produce a composition capable of easy manipulation inthe plastic and film-making, or varnish making or allied arts; but willnot injure or be injured by the substances with which it is associatedduring manufacture, storage or use. Still another object of my inventionis to provide a film having the hereinabove described properties. Otherobjects will hereinafter appear.

I have found that a composition having the desirable qualitieshereinabove enumerated can be obtained by mixing o'r compoundingcellulose ether, say for example an alkyl ether of the type described inU. S. Patent No. 1,-

188,37 6, June 20, 1916, Leon Lilienfeld, with ethylene glycol. Thismixing to a colloidized state is preferably performed with the aid of acommon solvent. While the details of one way of carrying out myinvention will be given by way of example, it will be understood that myinvention is not restricted thereto, except as indicated in the appended40 claim.

Ethylene glycol has the inherent characteristic of being a substantialnon-solvent of cellulose ether, especially water-insoluble ethylcellulose. By "non-solvent I mean that the addition of enough ofethylene glycol to a so- Application filed October 7, 1925. Serial No.61,142.

lution of cellulose ether will precipitate said ether from the solution?In carrying out one embodiment of. my invention, 100 parts ofWater-insoluble ethyl cellulose are dissolved along with from 10 to 50parts of ethylene glycol (say 20 parts) in from 300 to 500 parts of avolatile common solvent. The latter may usefully comprise a mixture ofmethyl acetate and methyl alcohol, the Weight of methyl acetate beingapproximately nine times the weight of the alcohol. ThlS composition issuitable. for spreadin upon a film-forming surface in a; coating, romwhich the volatile solvent evaporates sufliciently to leave atransparent flexible sheet, which is stripped off and otherwise treatedin the way well known in this art. The parts are by weight. Thetransparency and flexibility of the sheet show that the cellulose etherand the ethylene glycol remain in the colloidized state withoutprecipitating each other.

Where a more readily fiowable composition is desired, the amount ofvolatile solvent may be increased until the desired results areobtained; Benzol and ethyl or meth 1 alcohol may be added in thinning itout. f course, other equivalent volatile solvent mixtures may besubstituted. Moreover; ingredients which impart characteristicproperties to the film may likewise be added, such as triphenylphosphate, tricresyl phosphate, camphor, monochlornaphthalene, .etc. Thepropor-. tions of these substances, or mixtures of them, should not besuflicient to cause precipitation of the ether, or to cause whitefilms-or varnish coatings to be produced. The ingredients are of thecommercial type and sufliciently purified for the ends in view. Wherethe dope is to be made into sheets of films for photographic purposes,the substances are chosen orpurified to have the proper relative freedomfrom color.

Having thus described my invention, what Q0 2 I q r 1,735,158-

I claim as new and desire to secure by Letters Patent is:

As an article ofmanufacture, a film comprising water-insoluble alkylcellulose and 5 ethylene glycol, said film being formed from a,composition containing between 10 and 50 parts by Weight of ethyleneglycol for each 100 parts of alkyl cellulose, the proportions of theingredient being such that the film is 10 flexible and! transparent.Signed at Rochester, New York this 20th day of September, 1925,. v

STEWART J. CARROLL.

